Postpartum metritis is one of the most important disorders in cattle (Melendez et al., 2004). Approximately one third of postparturient cows develop metritis and 10 to 15% have clinical endometritis (Borsberry and Dobson, 1989). The consequences of metritis range from a subclinical infection, to illness with pyrexia, reduced milk yield, and occasionally death.
However, subclinical cases of metritis often progress to endometritis, which is an important cause of infertility and economic loss to the dairy industry (Gilbert et al., 2005). High prevalence rate of endometritis (53%) was found among US dairy herds using cytological methods for the diagnosis of uterine diseases (Gilbert et al., 2005).
Following calving, the uterus of over 90% of all cows becomes contaminated with bacteria (Sheldon et al., 2002), some of which are harmful and lead to establishment of infection and uterine disease (Bondurant, 1999). A diversity of bacteria can be isolated from the early postpartum uterine infection (Sheldon et al., 2004). Escherichia coli and Arcanobacterium pyogenes are the most common bacteria isolated from uterine infection, but other microorganisms such as Fusobacterium necrophorum, Prevotella melaminogenicus Pseudomonas spp., Streptococcus spp., Staphylococcus spp. and Bacteroides spp. are known to be responsible for puerperal metritis (Sheldon et al., 2004) {{48 Sheldon, I.M. 2004}}.
Ideally, therapy for uterine infection should eliminate pathogens from the uterus, and should result in a short as possible withdraw periods for milk and meat (Azawi, 2008). Although systemic or intrauterine antibiotic therapy is commonly used as the treatment of metritis (Azawi, 2008), it is recognized that antibiotic therapy cannot sterilize the uterus nor prevent recontamination that occurs during the early postpartum weeks (Sheldon and Dobson, 2004; Azawi, 2008). Furthermore, widespread usage of antimicrobials in food animal production has contributed to the emergence of antimicrobial resistance among pathogens that complicate the treatment of infectious diseases (Tollefson et al., 1999).
Additionally, the increasing level of resistance to frontline antimicrobial agents relevant to the treatment of human diseases is a significant public health concern (Tollefson and Miller, 2000) and has led to important changes in the perceptions and priorities of federal agencies with regard to antimicrobial usage as growth promoter and prophylactic agents (Angulo et al., 2004). US Food and Drug Administration (FDA), the United States Department of Agriculture (USDA) and the Center for Disease Control and Prevention (CDC) strongly promote the development of new classes of antimicrobials and other products able to eliminate or reduce risk of bacterial resistance (CDC Action Plan: On the world wide web at cdc.gov/drugresistance/actionplan/html/product.htm). The use of pathogenic-specific antimicrobials is expected to reduce the incidence of resistance development (Walsh, 2003).
Accordingly, what is needed in the art are alternative methods for preventing and treating uterine disease.